Dynamoelectric machine field core winding and method of construction



Dec. 3, 1968 R. J. MELVIN DYNAMOELECTRIC MACHINE FIELD CORE WINDIN ANDMETHOD OF CONSTRUCTION Filed April 1, 1966 INVENT'fiZ FaY J. MELVIN W,Mvm

Afrorzhgyg United States Patent 3,414,746 DYNAMOELECTRIC MACHINE FIELDCORE WINDING AND METHOD OF CONSTRUC- TION Roy J. Melvin, Waterford,Wis., assignor to MSL Industries, Inc., Racine, Wis., a corporation ofMinnesota Filed Apr. 1, 1966, Ser. No. 539,459 9 Claims. (Cl. 310-42)This invention relates to a field core winding and method ofconstruction.

The invention is shown as applied to the field of a universal A.C.-D.C.motor having its coil mounted on the core assembly by an automatic coilwinding equipment.

The core assembly is conventionally made by rive-ting togetherprefabricated laminations of desired form. Con ventionally, specialtooling has been used to support the winding turns until the winding hasbeen completed and its leads and end turns taped or clamped to the core.

In the preferred practice hereinafter described, the prefabricatedlaminations are assembled with straps having central portions offset tofit about the laminations (preferably in channels formed therein) andheld in the assembly by the rivets which pass through the laminations toconstitute the core.

It is contemplated that the straps will be electrically insulated eitherby coating them or sleeving tubes of electrical insulation over the endsof the straps or, as is preferred, by spraying the straps with aninsulating coating such as epoxy resin. conventionally, such a coatingis applied to the field core upon assembly of the laminations toconstitute such a core. Accordingly, it is preferred that the coating beapplied both to the core and to the straps after the straps are attachedby the rivets.

The laminations are desirably notched to provide the core with channelsto receive the offset portion of the straps. The ends of the straps areleft projecting out wardly and serve as guides about which thesuccessive turns of the coil winding are supported and located inpassing about the core from one set of poles to another. When thewinding is complete, the straps are folded down about the winding toanchor the several turns and the leads.

It will be noted that once the coil is complete and the straps foldedabout the turns, it is no longer necessary that the straps be anchoredto the core, since they are held in place by the winding. Hence, avariation in the foregoing procedure is possible, wherein the trapscould be temporarily attached to the core by means intended to beremoved when the winding is complete and the ends of the straps arefolded thereabout. However, the method first described is better andless expensive and is preferred.

In the drawings:

FIG. 1 is a view in perspective showing a field core having one of theturn-positioning and retaining straps applied to the laminations andanother one illustrated in outwardly spaced position in readiness forapplication when the remaining rivet is applied to hold the laminationsin assembly.

FIG. 2 is a view showing the completed core in end elevation with thewinding fragmentarily illustrated and retaining straps still projecting.

FIG. 3 is a view taken in section on the line 3-3 of FIG. 2 showing theassembly more advanced, the projecting ends of the strap at one sidehaving been folded down over the winding and the projecting ends of thestrap at the other side being in readiness for this final step.

FIG. 4 is a view of a modified embodiment on an enlarged scale and shownin cross section taken at the 3,414,746 Patented Dec. 3, 1968 "iceposition indicated at 4-4 in FIG. 1, the insulation having the form of atube sleeved over the projecting end of the strap.

The several laminations 6 of the magnetic core 8 are prefabricated inany desired manner. It is conventional to stamp these of magnetic ironto provide the poles shown at 10, 12, 14 and 16. They are provided withregistering holes 18 to receive rivets 20 for connecting them togetherunitarily. In accordance with the present invention, the severallaminations have registering notches which form slots 24 to receive theanchor straps contemplated for the practice of this method. By holdingthe laminations in temporary assembly in a jig, the channels 24 may bemachined in the laminations so positioned. However, it is preferred thatthe notches for forming these channels be stamped in the respectivelamination as shown in FIG. 1.

Separately prefabricated are the straps 26 which are conveniently madeof steel sufficiently stiff to support the coil while it is being woundand yet sufficiently llexible so that the strap ends can readily befolded about the end turns and terminal leads. Each such strap isprefabricated to provide a centrally offset portion 28 dimensioned toembrace the assembled laminations and adapted to seat in one of thechannels 24 and having projecting ends 30 which act as winding formsand, ultimately, as clamps. Intermediate the ends and the offset portion28 each strap has a portion 32 designed to seat against an end face ofthe core and apertured at 34 to receive a rivet 20.

The prefabricated straps may be rendered dielectric by being insulatedeither by coating or by applying an insulating sleeve such as is shownat 36 in FIG. 4. An epoxy resin such as is conventially applied to fieldcores is an example of an appropriate coating. The applied insulationshown at 36 may conveniently be made by cementing insulation to thestrip or by using extruded nylon or other synthetic resin in the form ofa prefabricated sleeve slipped over the end of the strip. Since the corehas to be insulated in any event, and since this is conventionally doneby spray coating, it is preferred that the uninsulated strips beattached to the laminations by the rivet 20 in the assembly of the coreand the entire unit may then be insulated by spray coating with epoxyresin or the like.

The coil is now wound turn by turn in situ, each turn passing about onepole and then passing about the outstanding end 30 of the respectiveform strip before passing the next pole. This procedure continues untilthe winding is complete. At the left in FIG. 3, the otherwise completewinding is shown at 40 before the ends 30 of the guide strip have beenfolded about it in the manner indicated by the arrows. At the right inFIG. 3, the ends 30 are shown folded over the winding 40 to confine theturns and to locate permanently and with precision the projecting leads42.

This completes the field assembly. The ends which originally served asguide for-ms in the winding of the turns now remain as clamps and aspermanent parts of the field. Use of special tooling of separatepreformed clamps in the manner of previous practice has been eliminated.

Mechanically, the field difiers from conventional practice in havingchannels in the laminations within which the said offset portions 28 ofthe guide and clamp elements 26 are recessed. Since these elementsremain as permanent parts of the assembly, it is significant that theyhold the coils and leads more securely and more neatly than heretofore.

In terms of the method, it is advantageous to use as coil winding formselements which subsequently become clamps as above described, each turnbeing located accurately by winding it in situ against a guide strip endwhich is then folded about the coil for clamping purposes.

I claim:

1. A field member comprising the combination with an assembly oflaminations having registering apertures to receive rivets, of windingguides and clamping strips having offset portions embracing thelaminations and having projecting ends, the coil having its turnsindividually wound upon the laminations and about such ends, and havingterminal leads, the ends of said strips encircling the coil as a meansof positioning the turns and anchoring the leads.

2. A field member according to claim 1 in which the said strips haveapertured portions registering with the apertures of the laminations,and rivets extending through the strips and the laminations andunitarily assembling said strips with said laminations.

3. A field member according to claim 1 in which the assembly oflaminations has channels in which the offset portions of said strips aredisposed.

4. A method of manufacturing a field member which comprises the steps ofprefabricating generally conventional laminations, positioning atopposite sides of said laminations guiding and anchor strips havingprojecting ends, winding in situ upon said laminations a coil havingturns passing about said strips and having terminal leads, and foldingthe ends of said strips about the turns of said coil.

5. A method according to claim 4 in which said strips are also foldedabout the terminal leads in a position for the anchorage thereof.

6. A method according to claim 4 including the step of fixing saidstrips to the laminations by extending fasteners through the strips andthe laminations to effect the unitary assembly of the strips andlaminations in advance of the winding of said coil.

7. A method according to claim 4 including the step of notching saidlaminations in registry to form channels at opposite sides of the core,forming the strips with offset central portions, seating said ofisetportions in respective channels and mechanically securing the respectivestrips and the laminations together in unitary assembly.

8. A method according to claim 4 including the further step ofelectrically insulating the assembly of the strips and the laminationsby spray coating such assembly when the strips and laminations have beenmechanically secured together.

9. A method according to claim 4 including the step of notching saidlaminations at corresponding points and assembling the laminations withthe notches in registry to form channels at opposite sides of the core,forming the said guiding and anchor strips with offset central portions,providing registering apertures in said strips and said laminations,seating the offset portions of the strips in the respective channelswith the said apertures in registry, mechanically securing therespective strips and laminations together in unitary assembly bypassing fasten ers through the aforesaid registering apertures, andelectrically insulating the unitary assembly of strips and laminationsby spray coating such assembly with a dielectric coating.

References Cited UNITED STATES PATENTS 3,030,528 4/1962 Dejean 310214 X3,145,313 8/1964 Tupper 310258 X 3,264,593 8/1966 Cole 310-2l4 FOREIGNPATENTS 1,320,580 1/1963 France.

MILTON O. HIRSHFIELD, Primary Examiner. WARREN E. RAY, AssistantExaminer.

1. A FIELD MEMBER COMPRISING THE COMBINATION WITH AN ASSEMBLY OFLAMINATIONS HAVING REGISTERING APERTURES TO RECEIVE RIVETS, OF WINDINGGUIDES AND CLAMPING STRIPS HAVING OFFSETS PORTS EMBRACING THELAMINATIONS AND HAVING PROJECTING ENDS, THE COIL HAVING ITS TURNSINDIVIDUALLY WOUND UPON THE LAMINATIONS AND ABOUT SUCH ENDS, AND HAVINGTERMINAL LEADS, THE ENDS OF SAID STRIPS ENCIRCLING THE COIL AS A MEANSOF POSITIONING THE TURNS AND ANCHORING THE LEADS.